Oxygen-delivering parachute escape outfit



Patented Oct. 10, 1944 UNITED STATES PATENT OFFEQE OXYGEN-DELIVERINGPARACHUTE ESCAPE OUTFIT Walter M. Boothby and William Randolph Lovelace,11, Rochester, Minn.

Our invention relates to an oxygen-delivering parachute escape outfitand has for its object to provide aviators and others, particularlymilitary aviators and observers who go to great heights in airplanes,with means for supplying oxygen to maintain consciousness during aperiod of descent when forced to bail out at such great heights becauseof wreckage or failure of the airplane. I

It is well known that satisfactory life conditions of individuals cannotbe maintained for long periods of time under barometric pressuresencountered at elevations much above 10,000 feet without addition ofoxygen which is delivered so as to maintain pressures in the alveolarregions of the lungs corresponding to a degree with those in normalliving ranges of barometric pressure. When elevations of 15,000 feet orover are reached it is absolutely essential to fortify both alveolarpressures and oxygen supply by adding oxygen. And when barometricpressures at elevations of some 35,000 feet or over are encounteredunconsciousness would ensue almost instantly (about thirty-five seconds)unless added oxygen is supplied to the lungs of a breather at such highaltitudes to maintain the partial pressure of oxygen at or near tonormal.

Means have been provided to furnish the aviator with an adequate supplyof oxygen in suitable quantities which are, because of the necessity ofconveying tanks of oxygen of considerable weight, necessarily in effectattached to and movable with the airplane itself. Hence, if the plane iswrecked or fails at high atmospheres and the aviator were to attempt tobail out it would be necessary to break the connection with the oxygensupply normally carried by the plane. Unconsciousness would immediatelyfollow and either the aviator would fail to clear the falling plane orif he did, would probably be unable to pull the ripcord for theparachute and his destruction would follow.

To meet the conditions prevailing where, especially in militaryaviation, high altitudes from 20,000 to 30,000 feet and even higher andcorrespondingly low barometric pressures are encountered, we havedevised a simple and eflicient means for providing an oxygen supply fora short time such that the aviator can transfer from the oxygensupplying means of the airplane and carry with him the necessary supplyof oxygen to maintain consciousness and life for the relatively shorttime to descend from the high altitude where bailing out becomesnecessary to the lower altitudes where safe breathing of external air ispossible.

It is the principal object of our invention, therefore, to provide suchmeans which include a small tank of oxygen at suitable pressurepositioned in a specially strongly reenforced pocket formed on theaviators clothing preferably reenforced by straps over the shoulder,with valve mechanism operable by a turn of the wrist and a maskstructure adapted to overlie the mouth of the aviator and having abreathing mouth turret adapted to be inserted m the mouth of the wearerand to be gripepd by his teeth.

It is a further object of our invention to provide such means having aszructure such that the transfer and resulting supplying of emergencyoxygen can be efiected with very great speed. When once eifected and thevalve to the tank is opened oxygen will flow from the tank and wil enterthe mouth at such a rate that the alveolar pressure of oxygen will be r.aintained nearly r-ormal and suflicient oxygen supplied even if thewearer may in part breathe through the exposed nasal passages, althoughmilitary aviators will doubtless be trained for mouth breathing undersuch conditions (a nasal clamp can be used if desired but training ofaviator is preferable).

It is a further object of our invention to provide simple suspensionmeans whereby the mouth gripping mask structure may be held suspendedbelow the mouth of a wearer where it can be 1nstantly slipped up intoposition to be gripped by the teeth, and wherein the suspension meanspreferably adjusted as to length before ascent is flexible and willexert some degree of pull in aiding in holding the mouth gripping maskupon the face of the wearer.

It is a further object of our invention to form the mouth mask structurewith laterally disposed wings and a promoting member having an elongatedopening therethrough, the whole assemblage being such that once grippedby the teeth of an aviator it will normally tend to be held in placeupon the aviator's face and will not easily 1 the teeth which willnormally be composed of relatively soft rubber material.

It is a further object of our invention to provide in connection withthe oxygen tank adapted to be secured in a pocket of the garment of theaviator a valve structure embodying a hollow valve stem, a tubeconnecting nipple extending beyond the operating handle and a limitedchannel through a portion of the-valve stem which will determine flow ofoxygen to the mask structure at a rate which, at the pressures at whichthe oxygen is being delivered will supply the mask structure withsufficient oxygen to maintain a safe supply thereof at safe quantitiesand With out waste to the breather.

The full objects and advantages 01 our invention will appear in thedetailed description there- I of hereinafter given and the novelfeatures by which the above outlined advantageous results are obtainedwill be particularly pointed out in r the claim.

' In the dlawing illustrating'an application of our invention in oneform,

Fig. 1 is a side elevation View of our complete parachute escape maskand. apparatus.

Fig.2 illustrates the manner in which the apparatus is positionedrelative to an air pilot or observer in an airplane when said pilot isbeing served with oxygen by devices more or'less permanently attached tothe airplane.

Fig. 3 shows the escape apparatus applied to the mouth of the wearerjust before he bails. out. Fig. 4 is an enlarged sectional view throughthe valve head or neck of the specially constructed tank, forcontrolling delivery of oxygen to the wearer.

Fig. 5 is a sectional view taken through the structure adapted to beheld in the mouth of the wearer which constitutes in effect a maskstructure'oi the oral type.

Fig.6 is a detail view showing the adjusted slot structure fordetermining'rate of flow of gas to the delivery tube.

As shown herein, our parachute escape a paratus comprises a mask ormcuth piece structure ID, a connecting tube therefor ii and a gascontainer 12. Under normal operative conditions the aviator or etherindividual is supplied with oxygen from tank fixed in position in theairplane through a tube l3 which goes to a. mask,

structure it of well known construction, held upon the face of theaviator by means of strap members 55 and wherein breathing takes placenormally with added oxygen delivered through tube l3 in connection witha rebreathmg bag it and escape valve mechanism ii.

The aviator will be provided with a pocket l8 along the trousers leg ofhis uniform. This pocket should be formed of very strong material and beheavily reenforced and firmly united with the garment to which it isattached and preferably Y will have added thereto a system of strapsupport (not shown) running over the shoulder of the wearer. Thereasonfor this heavy reenforcement in supporting the tank, comes fromthe fact that at jumping clear of the plane the aviator will gain greatspeed in falling before the ripcord can be pulled and the parachuteopened, and then there is a slight retardation of that descent, which,unless the tank is sufficientlyheld and supported as above noted, mightresult in its being torn loose, and so pulled away from the aviator andbe rendered useless for the purpose intended. And the mouth-piece maskill will be conveniently supported from the neck of the aviator justbelow his mouth, as shown in Fig. 2, so that in case of sudden necessityto bail out at high altitudes the aviator can quickly strip off his maskstructure l4, apply the mouth-piece mask Ill in place thereof, turn onthe oxygen from the small tank l2, by means hereinafter described, andjump clear of the falling airplane. He then will have a supply of oxygento maintain himself at least until he reaches such lower level as tohave sufficient oxygen and a sumciently high air pressure to maintainlife.

The tank I2 is provided with a neck member 20 which is shown somewhat indetail in Fig. 4. This neck member has a central opening 2| which isconnected at its bottom with a channel 22 leading to the interior oftank I! for gas passage. Threaded at 23 to the interior of chamber 2! isa valve stem 2-. having thereon a valve handle 25 by which the valvestem is rotated, such rotation causing it to move to and frnm theopening of channel 22 into a bottom chamber 26 below passageway 2!. Thevalve stem 24 has a channel or bore 21 extending through it which opensthrough a bore such as indicated at 28 into chamber 26.

Surrounding the opening of passageway 22 into chamber 26 is a valve seat30 which is engaged by the face of valve member 3! fast on valve stem24. A. nut 32 surrounds valve stem 24 and operates upon stufmg box 33 toseal valve stem 24 against escape of gas in any of its positions. Anopening 35 is normally closed by a cap member 35 and provides a way offilling the tank, being there connected by means not shown with a sourceof supply of dry oxygen gas under pressure so that when valve 3i istaken off of valve seat 30 and the opening 21 is closed by meanshereinafter described a supply of oxygen may be admitted into tank H]. Asafety plug 36 prevents the tank l2 being charged with an excessivepressure which might result in explosions. For safe operation or thisdevice at the very low temperatures (often minus at which it will beused, requires that the oxygen stored in the tank shall be absolutelydry.

The channel 21 in valve stem 24 is expanded at its upper part into alarger channel 31 in which is threaded a. member 38, Figs. 4 and 6,

providedwith a screw head 39 by means of which of flow will be greatestwhen the pressure of the tank is highest which will be at the highelevation when the escape apparatus is first put into use. The pressurewithin the tank and the consequent rate of flow will fall as the wearerdescends; but since he is constantly going into areas of higher andhigher barometric pressure this fall in oxygen pressure and rate ofdelivery to the aviator will be fully compensated. A look nut 82 holdsthe member 38 in its final adjusted position. As shown in Fig. 4 thisposition is that in which the channel or bore 21 is not blocked and theapparatus is in condition to be opened up for delivery of oxygen. Thisis effected, of course, merely by turning valve handle 25, one turn ofthe wrist being sufiicient.

, The tube H is connected with the valve stem 21 by being in effectscrewed on to the threaded end 43 thereof, this semi-permanent form ofattachment being essential to prevent jerking loose of the tube understress and excitement of the application of the apparatus in a fallingairplane.

The mask mouth-piece In is shown in detail in .Figs. 1 and 5. Itcomprises a body of rubber or similar material formed with a pair ofwings 44 and 45 with an intervening plateau portion 46 and a mouthturret 4'! formed with a bulge 48 which overlies an annular rim 49formed on a rigid member 50, of metal, Bakelite or the like, but strongenough to resist any compressive pressure of the jaws and teeth when thedevice is held in the mouth of the wearer. The opening in mouth turret41 is a fiat oval in form as shown in Fig. l and overlies an opening 52through rigid member so of the same general shape.

An opening 52 goes into a chamber 53 in which extends a turret member54. This turret member as preferably will have attached thereto a tube Hwhich extends some distance downwardly perhaps as much as six inchesfrom the mask body 50, and which provides a certain amount of reservoirand rebreathing capacity for escaping oxygen. In place of the tube Stunder certain conditions the turret 54 may be formed as shown in Fig. 5and may be provided with a sponge rubber control valve 55 across anopening 56 going to atmosphere. It is preferred, however, not to use thesponge rubber disc arrangement for the reason that at excessively lowtemperatures where the device may be used there is danger of ice formingon the disc, which would hamper or prevent respiration.

The chamber 53 has an opening 5'! extending therefrom and a tubularextension 58 which receives a hollow connector member 59. The tube II isunited at 60 with the connector member 59.

' A band indicated at 6!, Fig. 5, composedof rela tively soft rubber isapplied to the neck of the turret extension 41 providing a body of softmaterial to be gripped by the teeth.

A band 65 of elastic material has an opening therein indicated at 66 sothat portions of the band 6'! and 68 lie on either side of the plateauextensions 46. As shown in Fig. 2, theband will be adjusted to theweather so that under normal operation when applied to the neck of thewearer it will hold member Hi just below the chin of the 'wearer whereit can be quickly brought to the mouth when the normal mask I4 is takenoff.

The advantages in operation of our escape device are, or course,primarily that it provides a certain and safe adjunct to an aviatorsequipment which will enable him to leave the airplane and its oxygensupply secured thereto and to maintain himself during parachute descentfrom high elevations and consequent low barometric" pressures.

' oxygen from the tank in the pocket of his trousers It may be assumedthat the aviator isin the position of Fig. 2 employing-the mask forprovidingthe regular oxygen supply from the'tank carried in the airplanewhen, either from enemy action Or from other cause, the airplane is put5 out of commission and begins to fall. The aviator has, of course,strapped to him in the customary manner, a parachute and to save himselfhe must get clear of the falling plane and descend by the well knownsupport of the parachute. Practically with a single movement he willthrust off the mask structure he is wearing and place the mouth-piece ofthe emergency mask structure between his teeth where the grip uniformand then will proceed to make other necessary preparations to jump. Asmentioned before, the aviator has at most thirty-five seconds ofconsciousness at the barometric pressure of 35,000 feet of elevation ifthe regular oxygen supply is cut off, therefore his first concern inpreparing to bail out must be to establish feed of emergency oxygen, andour apparatus is particularly designed to enable him to do this, thatis, to shift from the normal oxygen supply of the airplane to theemergency supply in the shortest possible time.

This whole procedure will take hardly a second' more than jumpingwithout the emergency oxygen supply. Of course when the aviator is freefrom the plane he will pull the rip-cord and the parachute will becomedistended and his descent under parachute support will take place. Thisdescent will be at a more rapid rate in higher altitudes wherebarometric pressures are low than as the aviator gets farther down. Hewill have a supply of oxygen in the small tank to last him for somethinglike 14 minutes, at the expiration of which period he may have landed onthe ground, and very certainly would have reached an atmosphere of safebarometric pressure where the mouth-piece mask can be discarded andnormal breathing resumed.

The valve structure is such that a single turn of the valve handle willproduce delivery of oxygen at maximum volume for the tank pressure whenthe valve is opened. The limit groove connected with the valve stemopening and the relatively large valve area opened by turning of thevalve stem insures this. And as already stated, the high pressure ofoxygen in the tank at the start will increase delivery of oxygen at thebe ginning of descent where greater volume of oxygen and more pressurein the alveolar regions of the lungs are desirable. The descent fromhigher to lower elevations and consequent increasing barometric pressurewill accompany the gradual decrease of pressure from the oxygen tank,and. will about compensate one another. The aviatsr under normalconditions will breathe exclusi through the mouth and will rebreatheexhala= n and draw back oxygen tending to escape through and filling thetube 5t. Even though at the start temperatures are extremely low thereis nothing to freeze shutprovided dry oxygen has been used in fillingthe tank. Once the descent has safely begun it will continue withoutincident until the aviator makes a successful landing on the ground,

The structure of theentire apparatus is very simple yet of such a naturethat it cannot fail ,in operation. The gauge 65 on the side of the tankneck is provided so that wheneyjer the aviator puts the oxygen tank inthe trousers pocket that the entire apparatus is in working orderwhenever he enters a plane thatwill ascend to above 30,000 feet.

We claim:

In a parachute escape device adapted to be substituted quickly fornormal means of supplying oxygen in an airplaneat high elevations, atank of oxygen secured in a pocket of the aviator and being of a sizeand having the oxygen at a .pressure to provide a sufficient quantity ofoxygen as delivered to the aviator to supply oxygen for safe descentwith a parachute from such high elevation, a mouth mask structureadapted to be quickly inserted in the mouth to be gripped by theaviators teeth to hold. it in position therein and to permit breathingtherethrough having means to resist collapse from the grip of the teeth,said mask being connected with the oxygen tank and being normallysupported upon the person of the aviator in convenient position quicklyto be inserted in his mouth, a valve on the tank having a handle adaptedto open the valve for delivery of full maximum flow of oxygen to themask resulting from a single turn of the valve handle, and an exhalingvalve and extended discharge tube leading therefrom and providing aheating reservoir and partial rebreathing chamber.

WALTER M. BOOTHBY.

WILLIAM RANDOLPH LOVELACE, II.

